setup_terraform doesn't help manage multiple environments / task runner replacement

[JimCircadian]

The overwriting and installation of secrets and caches in the terraform directory is not helpful for managing multiple environments (dev, stg, prod.) Ideally we'd use a task runner like fabric for managing all this rather than a shell script, as we can then add tasks for running terraform with environment specific caches/secrets/arguments.

• Work out how to manage multiple environments with existing setup
• Replace setup_terraform with task runner
  • Set up terraform with this, isolated from existing environment
  • Run terraform with new task
  • Destroy infra with new task
• Remove setup_terraform
• Port as (submodule'd repository?) default task runner for terraform across others repositories
  • icenetevtproc
  • icenetgeoapi

[JimCircadian]

Any task running is no longer required in evtproc and geoapi as they're no longer administering terraform. This can be isolated within the icenet-etl repository, but does need a better solution for multiple environments still.

[JimCircadian]

We should now be safe to have multiple initialised providers using setup_terraform. Ultimately it'd be better to register new run directories and states via separate run directories so that different Azure tenancies can be used without reinitialisation, but that's not a priority at present.